Friction-gear.



G..A. J-UHNSON.

FmcloN GEAR. l APPLICATION FILED DEC. 1'6. |916.

1h31: melma Feb. 5,1919.

INVENTOR. WJTNESSES: f 1f: y 'aayge/uwan anteriori-eraan.

.application tiled December 16, 1916. SeraI No. 137,359. i

To all 'whom it may concern: l

Beit known that 1, GEORGE A. JOHNSON, a citizen of the United States,residing at Chicago, in the county of Cook and State'of llllinois, haveinvented a certain new and useful Improvement in Friction-Gears, ofwhich` the following is a full, clear., concise, and Aexact description,reference being had to the accompanying drawings, forming.

tiple part main and auxiliary wedges.

Another and more speciiic obJect of thek invention is to provide acollapsible wedge wherein are employed a series of wedges correspondingto the number of friction shoes and a non-wedgingplug mounted betweenthe wedges for the purpose of maintaining the latter in their fullyexpanded or operative position during the act of compression, the plugbeing so designed as to be readily releasable upon removal of thepressure, to thereby permit the wedges to collapse and relieve thepressure against the shoes.

1n the drawing` forming a part of this specification, Figure 1 is alongitudinal, sectional view of a draft rigging showing my improvementsin connection therewith, some parts being shown in side elevation. Fig.2 1s a front end elevation of the improved gear. Fig. 3 is a vertical,sectional view showing more particularly the friction elements and takenon the line 3*?) ofFig. 1. And ligs. 1' and 5 are detail perspectives ofone of the wedges and one :of the friction shoes, respectively, Y

In' said drawing, 10 indicates one of the draftl sills of a car, 11 arear stop, 12 a front stop, 13 a draw bar, 14 a yoke secured to` thedraw bar, 15 a front follower', 16 a rear' follower, and 17 a saddleplate for holding the parts in position. All of the foregoing may be ofwell known or standard construction.

The improved gear proper, as shown, comprises a combined friction shelland spring' casing designated generallymby the reference A., the sainehaving a cylindrical Vfriction shell proper 18 at the front end and aspring casing 19 at the rear of the friction shell. Coperable withthemember A is a circularly arranged set of yfriction shoes 20-20, each ofthe shoes 20having an outer cylindrical surface 21 coperable with theinterior friction surface of the shell 18. On its inner face, eachfriction shoe 20 is provided with a wedging surface 22 which may be maderelatively acute, in view of the collapsible wedge hereinafterdescribed. The shoes 20, at their `rear or inner ends bear against awasher 23 against which bears the outer end of the heavy coil 24 of thespring of the gear, the rear end of said coil 24 bearing against theintegral rear wall 25 of the member A. Mounted within the frictionshoes2O is a collapsible wedge, the same comprising aseries of wedge elements26' equaling in nurnber the number of friction shoes. Each of the wedgeelements, 26 is provided with an exterior wedge surface 27 correspondingto and engaging the opposed wedgingV surface 22 of the friction shoe.,As clearly appears from Fig. 8, the wedge elements .26 are seatedwithin the shoes and preventedfrom circumferential displacement withrespect thereto by means of the scctio s 2'8-28 of the shoes As clearlyindicatel in Fig. 1,

the wedge elements 26'beai directly against the front follower 15 and inorder 'to prevent the wedge from collapsing during action of the gearand to maintain the collapsible wedge in fully expanded operativeposition, 1 Vhave provided a loose plug 29 which is conical form and hasits surface contacting the corresponding conical surfaces 30 on theinner faces of the wedge elements 26.

In the drawing, a relatively slight clearance is indicated between theouter face 31 of the plug and the inner face of the front follower, butthis amount of clearance is greatly exaggerated in the drawing in orderto prevent possible misconception as to the action of the plug 29. 1nactual practice, said outer face 31 will be made iush with the outerends of the wedge elements 26 so far as possible, but in order toprevent any possibility of the face 31 projecting beyond lthe outer endsof the' wedge elements 2G and thereby creating a wedging action betweenthe plug 29 and said wedge elements, said being on the safe side toprevent wedging action. The function of the plug 29, under compressivemovements, is merely to`hol'd the wedge elements in fullyexpanded'position for the purpose hereinafter described. It will benoted that. the angle of Contact between the conical surface of the plug29 and the surfaces 30 of the wedge elements is relatively blunt. Attheir inner ends, the Wedge elements 26 bear against a washer 32 whichfits within `the inner ends of the friction shoes and the inner coil 33of the spring of the gear bears against said washer 32 at its front end,the rear end of said coil 33 bearing against said wall 25.

In operation, upon'V inward movement of the draw bar, it is apparentthat pressure will be transmitted through the follower 15v directly tothe wedge elements 26.. The latter, which form the collapsible wedge,are prevented from collapsing by the plug 29 and on account of therelatively acute angle between the wedging faces of the collapsiblewedgey and friction shoes, a greatly multiplied pressure is transferredto the friction shoes and from the friction shoes to the friction shell.It is obvious that the inward movement of the friction shoes is resistedby the outer coil of the spring and the collapsible wedge is resisted bythe inner coil of the spring. With this arrangement, a large capacity isobtained due to the acute angle between the wedge and the shoes. Uponremoval of the pressure, that-is, during release, the loose plug 29 willdisengage itself freely from the elements of the collapsible wedge sincethere is no wedging action between said plug and the wedge. This permitsthe wedge to collapse, which action is `assisted by the inner coil 33and thus relieves the pressure against the friction shoes and insures asatisfactory release.

Heretofore, where an acute angle has been employed between a wedgingelement and the friction shoes, while it has been possible to obtainhigh capacity, such gears did not readily release, but stuck when anyheavy blow was imposedthereon. Vhen a blunt angle has heretofore beenused between a wedging element and the friction shoes, it was possibleto obtain. the release, but the capacity remained low. Vlith myarrangement, I am enabled to employ the acute angle between the wedgeand the' friction shoes and because of the loose'plug, which is notwedged against the wedging elements 26, a certain and easy release isobtained, thus providing a friction gear that is relatively cheap tomanufacture and possessing the advantages of more expensive frictiongears having various expedients to insure release.

Although I have herein shown and described what I nowv consider thepreferred embodiment of the invention, the same is merely illustrativeand I contemplate all changes and modifications that come within thescope of the claims appehded hereto.

I claim:

1. In a friction gear, the combination with a friction shell, offriction shoes coperable therewith and having interior wedge faces, aplurality of wedge elements coperable with said shoes, and loose meanswithin said wedge elements for maintaining the latter in' l expanded,operative condition during compressive action of the gear, said elementsand said means acting substantially as a solid unit to wed e the shoesoutwardly, said means upon release action being free to moveindependently of said elements and thereby permit collapse of saidelements. Y 2. In a .frictional shock absorbing mechanism, thecombination with a friction shell, of a plurality of friction shoes coerative therewith and having Wedge surfgces on their inner faces,resilient, means for resisting movement of the shoes with respect to theshell, and a lurality of members located centrally o said shoes andadapted to act as a solid wedge in coperationwith said shoes under.compressive action of the gear, one of said members being free tol moveindependently of the other members durinv release and permit collapsethereof. 3. fin a friction gear, the combination with a friction shell,of friction shoes cooperable with said shell, a collapsible wedge, afollower located adjacent said wedge, the parts being so arranged thatressure is transmitted directly from the ollower to the wedge in linesparallel to the axis 'of the gear, and means associated with the wedgefor retaining the latter in operative ex- .panded condition whenpressure is so transmitted, said means having movement independently ofsaid wedge during release and after removal of pressure to therebypermit the wedge to collapse.

4. In a friction gear, the combination with a. friction shell, offriction shoes coperable with said shell and having interior wedge facesat an acute angle to the axis of the shell, a spring for resistingmovement of said shoes, wedge elements coperable with and correspondingin number to said friction shoes, and a non-wedge-acting plug locatedwithin the Wedge' elements, the parts being so arranged that pressure istransmitted to the wedge elements in lines parallel to the axis, thenfrom the wedge elements through the coacting wedge faces to the shoes atan acute angle to the axis of the shell and finally from the shoesradially to the friction shell, said plug and wcdgevelements acting as aunitary wedge in compressive action and the plug being readilyreleasable with respect to said elements under release.

5. In a.' frictional shock absorbing mechaigzsspisi mism of thecharacter described, the combination with a friction shell havingfriction surfaces on its interior, of :iV piui'ality of :friction shoeshaving friction suiiaces on their outer faces copembie with the friction surfaces of the siieii, eachoi seid shoe being provided on itsinner face-With a Wedging surface et an acute angie to the axis of theshell, spring means for resising relative movement between the shoes amshell, ai plurality oi' Wedge eiements disposed Within the shoes ,andhaving outer Wecige surfaces coperabie with the Wedge surfaces of theshoes, said Wedge elements having inclined surfaces on their inner:faces and at a bluntei angie to the axis ofihe siieii than the Wedgeeilrfacss of the shoes, nd

:i ping ffii-ting Within the Wege elements and having its outeif endsurface substantially ush with the outei.' ends of the Wedge eiementswhereby, saisi eements emi plug aci: substaiitiaiiy :is a solidi. Wenigeduring; eompressive action of the mechsiiism 'and there by a highzictioai capacity is producefi because of the acute between. Wedgeelements ami shoes, smi 'die plug is movable -ineiepcncemziyof the'wedge eiements under reieese to permit coiiapse ci seid eiemeiits anddisengagement from the shoes v iin witness that .i claim the oifcgoing ihave heieimco subscibe my name 'this Mtb day of December, 19N.

A. JHNSN.

